Your best option is playing this 5.1.2 Dolby Atmos Test Tones MP4 video. Download it onto a USB flash drive and plug it into your TV or AirPlay it from an iOS device to a Roku Ultra or Apple TV 4K connected to your TV. If you AirPlay the video, check the Sonos app to confirm it is playing in Dolby Atmos:

https://download.dolby.com/us/en/test-tones/dolby-test-tones_5_1_2.mp4

Hi GuitarSuperstar,

Thank you. Will check it out. Would be great if Sonos added a diagnostic feature putting tones through each speaker. Perhaps part of Trueplay..

Yep 

I don’t think test tones on a wireless system are really that important, the way it is on a wired system.  On a wired system, where the receiver sends out a signal to the speakers and doesn’t know if a speaker is actually connected, it makes sense.  With Sonos, the speakers are in communication with each other, and thus can confirm the connection.  Indeed, if you unplug your sub from power for example, the Sonos will tell you the sub is missing.

The vast majority of issues in this area I’ve seen is that customers aren’t sure if the content they are playing is coming in as surround sound or atmos.  Test tones aren’t going to help you with that.  And Sonos has attempted to address that by stating the audio format received in the Sonos app.  

That said, I can see where test tones could be helpful in making sure the rear and height channel volumes are set the way you want them.  Not sure if setting volume levels this way would translating into better sound when all the channels are playing though.

Thanks Danny. 
 

The reason I ask is that I have a Sonos Arc and heard a POP sound and unsure if one of the many speakers within it is now dead.

anyway to reliably confirm if there is a problem or not?

would the Sonos app alert me if there was a problem with an individual speaker/driver within the Arc. 
 

Yep 

I was thinking about that right after I posted.  Good point.  A test track still may not be terribly helpful since the Arc has a lot more amps and speakers in it then the channels it supports.  Some channels split between woofers and tweeters..  And the issue could be amp, not speaker.

I think a diagnostic might be the best way to go for that case. I don’t know if support would be able to tell your specific issue with a diagnostic, but they have identified hardware failures via diagnostic before.

I simply use a cheap dual-head stethoscope to check out the individual drivers, along with a pink noise test track.

I support this..Sony does it on their soundbars and so Sonos can easily implement it. It's basically white noise that Sony generates with their built-in UI on their bars.